A32 year old man presents with a 5 year history of vomiting. The vomiting is virtually continuous for 7 days. During the episodes he also has severe generalized abdominal pain. This is also associated with diarrhea, occasionally with blood. He seeks a dark room and puts himself in a ball lying on his side. He often has to go to the ED for IV fluids. He may lose up to 20 pounds during an episode. Between these 7 day episodes he is asymptomatic. They occur every 6 months. Each episode is a carbon copy of the others. There is no warning that these episodes are coming on.
UNUSUAL CAUSES OF ABDOMINAL PAIN
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ANSWER AND DISCUSSION
Diagnosis: Cyclic Vomiting Syndrome (CVS)
First described in France in 1861, the definition requires 4 items: 1) Three or more recurrent discrete episodes of vomiting; 2) Varying intervals of completely normal health between episodes; 3) Episodes are stereotypical with regard to timing of onset, symptoms, and duration; 4) Absence of an organic cause of vomiting. Some have suggested that it is necessary to rule out CNS tumor, malrotation of the gut and kinked ureter (IVP or CT with pain). Rome III criteria include: 1) Stereotypical episodes of vomiting regarding onset (acute) and duration (< 1 week); 2) Three or more discrete episodes in the prior year and 3) Absence of nausea/vomiting between episodes.
CVS was seen more frequently in children who would average 12 episodes per year. The literature is not clear on a sexual preference in children. In 1999, Prakash and Clouse reported on 17 cases of adult CVS over 10 years with the average age at onset of 35 years (14-73); average age at diagnosis: 41 years with no sexual preference. The average episode length was 6 days (1-21 days); symptom free interval was 3 months (0.5-6 months) with an average of 4 cycles per year.
The cause of this disorder is unknown but some patients seem to have a mitochondrial variant. >50% of CVS patients may have maternal inheritance of a mitochondrial DNA sequence variation.
Cyclic vomiting is considered to have 4 phases: Phase 1: Asymptomatic; Phase 2: Prodrome (many patients have no prodrome); Phase 3: Full blown vomiting episode; Phase 4: Recovery.
Patients who have multiple severe episodes may respond to prophylaxis with tricyclics, sometimes at doses > 100 mg per day. Cyproheptadine has been said to be therapeutic in some cases. Occasional patients may find some relief from Coenzyme Q-10 and/or l-carnitine. During the Prodrome stage the goal is to abort the episodes. Ondansetron and/or Aprepitant may be helpful. Most patients are very anxious in this prodrome period and may have a lessening of their anxiety with benzodiazepines. During the full blown vomiting episode the patient should be considered a medical urgency and should be admitted to the ED as quickly as possible with the objective to heavily sedate the patient, the theory being if the head is put to sleep then the CVS will go away.